The identification of the weak oestrogen equol [7-hydroxy-3-(4′-hydroxyphenyl)chroman] in human urine

The identification (by gas chromatography–mass spectrometry and n.m.r.) for the first time of the weak oestrogen equol [7-hydroxy-3-(4′-hydroxyphenyl)chroman] in human urine is described. Preliminary results of its quantitative excretion in urine are reported and the potential significance of the occurrence of this compound is discussed.